Add TF_HOSTNAME_KEY_NAME to specify which hostname to return (#94)

Overwrite with the environment variable TF_HOSTNAME_KEY_NAME which attribute is to be used for the ansible inventory name. By default, the IP address is used. The Ansible variable "ansible_host" is used to connect to the host.

README.md

@@ -147,6 +147,11 @@ to `private_ip` before running the playbook, like:
 
 	TF_KEY_NAME=private_ip ansible-playbook --inventory-file=/path/to/terraform-inventory deploy/playbook.yml
 
+By default, the ip address is the ansible inventory name. The `TF_HOSTNAME_KEY_NAME` environment variable allows
+you to overwrite the source of the ansible inventory name.
+
+	TF_HOSTNAME_KEY_NAME=name ansible-playbook --inventory-file=/path/to/terraform-inventory deploy/playbook.yml
+
 ## Development
 
 It's just a Go app, so the usual:

cli.go

@@ -55,20 +55,20 @@ func gatherResources(s *state) map[string]interface{} {
 
 	for _, res := range s.resources() {
 		// place in list of all resources
-		all.Hosts = appendUniq(all.Hosts, res.Address())
+		all.Hosts = appendUniq(all.Hosts, res.Hostname())
 
 		// place in list of resource types
 		tp := fmt.Sprintf("type_%s", res.resourceType)
-		types[tp] = appendUniq(types[tp], res.Address())
+		types[tp] = appendUniq(types[tp], res.Hostname())
 
 		unsortedOrdered[res.baseName] = append(unsortedOrdered[res.baseName], res)
 
 		// store as invdividual host (eg. <name>.<count>)
 		invdName := fmt.Sprintf("%s.%d", res.baseName, res.counter)
 		if old, exists := individual[invdName]; exists {
-			fmt.Fprintf(os.Stderr, "overwriting already existing individual key %s, old: %v, new: %v", invdName, old, res.Address())
+			fmt.Fprintf(os.Stderr, "overwriting already existing individual key %s, old: %v, new: %v", invdName, old, res.Hostname())
 		}
-		individual[invdName] = []string{res.Address()}
+		individual[invdName] = []string{res.Hostname()}
 
 		// inventorize tags
 		for k, v := range res.Tags() {
@@ -77,7 +77,7 @@ func gatherResources(s *state) map[string]interface{} {
 			if v != "" {
 				tag = fmt.Sprintf("%s_%s", k, v)
 			}
-			tags[tag] = appendUniq(tags[tag], res.Address())
+			tags[tag] = appendUniq(tags[tag], res.Hostname())
 		}
 	}
 
@@ -94,7 +94,7 @@ func gatherResources(s *state) map[string]interface{} {
 		sort.Sort(cs)
 
 		for i := range resources {
-			ordered[basename] = append(ordered[basename], resources[i].Address())
+			ordered[basename] = append(ordered[basename], resources[i].Hostname())
 		}
 	}
 
@@ -187,8 +187,10 @@ func checkErr(err error, stderr io.Writer) int {
 
 func cmdHost(stdout io.Writer, stderr io.Writer, s *state, hostname string) int {
 	for _, res := range s.resources() {
-		if hostname == res.Address() {
+		if hostname == res.Hostname() {
-			return output(stdout, stderr, res.Attributes())
+			attributes := res.Attributes()
+			attributes["ansible_host"] = res.Address()
+			return output(stdout, stderr, attributes)
 		}
 	}
 

parser_test.go

@@ -3,12 +3,52 @@ package main
 import (
 	"bytes"
 	"encoding/json"
+	"os"
 	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+const exampleStateFileEnvHostname = `
+{
+	"version": 1,
+	"serial": 1,
+	"modules": [
+		{
+			"resources": {
+				"libvirt_domain.fourteen": {
+					"type": "libvirt_domain",
+					"primary": {
+						"id": "824c29be-2164-44c8-83e0-787705571d95",
+						"attributes": {
+							"name": "fourteen",
+							"network_interface.#": "1",
+							"network_interface.0.addresses.#": "1",
+							"network_interface.0.addresses.0": "192.168.102.14",
+							"network_interface.0.mac": "96:EE:4D:BD:B2:45"
+						}
+					}
+				}
+			}
+		}
+	]
+}`
+
+const expectedListOutputEnvHostname = `
+{
+	"all":	 {
+		"hosts": [
+			"fourteen"
+		],
+		"vars": {
+		}
+	},
+	"fourteen":	 ["fourteen"],
+	"fourteen.0":	 ["fourteen"],
+	"type_libvirt_domain": ["fourteen"]
+}`
+
 const exampleStateFile = `
 {
 	"version": 1,
@@ -633,6 +673,7 @@ olddatacenter="\u003c0.7_format"
 
 const expectedHostOneOutput = `
 {
+	"ansible_host": "10.0.0.1",
 	"id":"i-aaaaaaaa",
 	"private_ip":"10.0.0.1",
 	"tags.#": "1",
@@ -665,6 +706,33 @@ func TestListCommand(t *testing.T) {
 	assert.Equal(t, exp, act)
 }
 
+func TestListCommandEnvHostname(t *testing.T) {
+	var s state
+	r := strings.NewReader(exampleStateFileEnvHostname)
+	err := s.read(r)
+	assert.NoError(t, err)
+
+	// Decode expectation as JSON
+	var exp interface{}
+	err = json.Unmarshal([]byte(expectedListOutputEnvHostname), &exp)
+	assert.NoError(t, err)
+
+	// Run the command, capture the output
+	var stdout, stderr bytes.Buffer
+	os.Setenv("TF_HOSTNAME_KEY_NAME", "name")
+	exitCode := cmdList(&stdout, &stderr, &s)
+	os.Unsetenv("TF_HOSTNAME_KEY_NAME")
+	assert.Equal(t, 0, exitCode)
+	assert.Equal(t, "", stderr.String())
+
+	// Decode the output to compare
+	var act interface{}
+	err = json.Unmarshal([]byte(stdout.String()), &act)
+	assert.NoError(t, err)
+
+	assert.Equal(t, exp, act)
+}
+
 func TestHostCommand(t *testing.T) {
 	var s state
 	r := strings.NewReader(exampleStateFile)

resource.go

@@ -164,6 +164,17 @@ func (r Resource) NameWithCounter() string {
 	return fmt.Sprintf("%s.%d", r.baseName, r.counter)
 }
 
+// Hostname returns the hostname of this resource.
+func (r Resource) Hostname() string {
+	if keyName := os.Getenv("TF_HOSTNAME_KEY_NAME"); keyName != "" {
+		if ip := r.State.Primary.Attributes[keyName]; ip != "" {
+			return ip
+		}
+	}
+
+	return r.Address()
+}
+
 // Address returns the IP address of this resource.
 func (r Resource) Address() string {
 	if keyName := os.Getenv("TF_KEY_NAME"); keyName != "" {